JPH0450097Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an injection molding machine that performs molding by forcing resin into a mold.

(Prior Art) In an injection molding machine, injection is performed by touching a nozzle at the tip of a heating cylinder to a mold. For this purpose, the mold is provided with a recessed nozzle touch portion that communicates with the sprue.

By the way, the injection device main body equipped with a heating cylinder is movable forward and backward relative to the mold, and moves forward during injection so that the nozzle comes into contact with the nozzle touch portion of the mold. The movement of the injection device main body back and forth is normally performed by a cylinder, and the operation of the cylinder is stopped when the nozzle comes into contact with the nozzle touch portion. In other words, a signal indicating that injection is possible is obtained by detecting that the nozzle has come into contact with the nozzle touch, and this position detection is normally performed by a limit switch.

That is, a limit switch is attached to a slide base on which the injection device is movable, and a cam is attached to the main body of the injection device, and the cam and limit switch are connected so that the time when the cam contacts the limit switch and the time when the nozzle contacts the nozzle touch portion coincide with each other. The positional relationship is set in advance, and a signal indicating that injection is possible is obtained by operating a limit switch.

(Problem to be solved by the invention) In the above conventional example, injection is performed on the assumption that the nozzle comes into contact with the nozzle touch part when the limit switch operates, but in reality, the cylinder does not operate. Even if the nozzle stops, the nozzle is not in contact with the nozzle touch part, and if the cylinder stops at the stroke end, the touch force may be completely insufficient. If injection is performed in this state, some of the molten resin may be Instead of entering the sprue of the mold, it scatters to the outside from the nozzle touch.

The present invention was made in order to solve the above problems, and its object is to provide an injection molding machine that does not cause molten resin to scatter during injection.

(Means for Solving the Problems) The present invention includes a detector that detects when the injection device body reaches the cylinder stroke end position, which is further advanced from the nozzle touch setting position, and outputs a signal. The output of this signal disables injection.

(Function) When the injection device main body moves forward with respect to the mold and the nozzle at the tip of the heating cylinder reaches the nozzle touch setting position, the operation of the cylinder is stopped by the output signal from the second detector (limit switch 11). The state is set to start injection.

Next, if the injection body reaches the cylinder stroke end position while advancing a further minute distance to the actual nozzle touch, the first detector (limit switch 10) detects this and disables injection. do.

(Example) Examples of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes an injection device main body, which has a heating cylinder 2, and a nozzle 3 is attached to the tip of the heating cylinder 2. A slide base 4 is fixed on a base 5, and the injection device main body 1 is movably set on the slide base 4. 6 is a mold, a fixed side mold 6 attached to a fixed platen 7
a, and the movable side mold 6b attached to the movable platen 8
As shown in FIG. 2, the stationary mold 6a is provided with a nozzle touch portion 9 formed in a concave spherical shape.

The injection device main body 1 is mounted on the slide base 4 and the mold 6 is mounted on the slide base 4.
The injection device main body 1 can move forward and backward with respect to the main body 1, and the movement of the injection device main body 1 is performed by a cylinder (not shown).

Three first, second, and third limit switches 10, 11, and 12 are attached to the slide base 4 at predetermined intervals along the forward and backward movement direction of the injection device main body 1. Three first, second, and third cams 13, 14, 1 that can freely come into contact with the respective limit switches 10, 11, 12.
5 are fixed, the first limit switch 10 is located closest to the mold 6, followed by the second limit switch 11 and third limit switch 12, and similarly, the first cam 13 is located closest to the mold 6. The cams are located closer to the mold, followed by the second cam and then the third cam. The first limit switch 10 is connected to the first cam 13, the second limit switch 11 is connected to the second cam 14, and the third limit switch 11 is connected to the second cam 14.
The limit switches 12 are able to come into contact with the third cams 15, respectively.

These limit switches are for detecting the position of the injection device main body 1, and the second limit switch 11 is for detecting the position of the injection device main body 1 and the nozzle 3 when the injection device main body 1 moves forward.
The first limit switch 10 is for detecting the position before the nozzle touch part 9 of the mold 6 contacts (touches) the nozzle touch part 9. The third limit switch 12 is for detecting the position at which the injection device body 1 stops and cannot be advanced any further, that is, the cylinder stroke end position. Note that the limit switches 11 and 12 are adjustable in position.

Here, the limit switches 11 and 12 and the related cams 14 and 15 determine the moving distance of the injection device main body, and it is possible to fix one of them and make the position of the other adjustable. .

Next, the operation of the injection molding machine having the above configuration will be described. The injection device main body 1 moves forward, and the first and second limit switches 10 and 11 come into contact with the first and second cams 13 and 14, respectively, and operate to output a signal. Figure 3 shows this state.
In this case, even though the nozzle 3 appears to be in contact with the nozzle touch part 9, the touch force of the nozzle 3 may not be sufficient, and when the first and second limit switches 10 and 11 are operated, injection is disabled. ing.

In other words, the second
The limit switch 11 is set slightly in front of the actual nozzle touch position to facilitate touch position adjustment.

Therefore, the injection device main body 1 further advances slightly until the nozzle 3 comes into contact with the nozzle touch portion of the mold.

However, within this movement range, when the cam 13 that has moved together with the injection device main body 1 contacts the first limit switch 10 and turns on, that is, when the cylinder reaches the stroke end where it cannot move forward until the nozzle touch position. prevents molten resin from being injected from the nozzle in response to a signal from the first limit switch 10.

Next, as shown in FIG. 4, the second limit switch 11 is operated, and the first limit switch 10 is not yet operated by the first cam 13, that is, the injection device main body 1 is at the stroke end of the cylinder. In the preliminary stage, the nozzle touch is actually completed and the injection device main body 1 is prevented from moving forward, so the touch force of the nozzle 3 becomes sufficient and injection becomes possible.

When the injection is completed, the injection device main body 1 begins to move backward, and stops moving back when the third limit switch 12 comes into contact with the third cam 15.

(Effect of the invention) As explained above, in the present invention, injection is disabled until the nozzle contacts the nozzle touch part of the mold with sufficient touch force, so the nozzle touch force remains insufficient. Injection is not performed, so molten resin does not scatter to the outside from the nozzle touch.

[Brief explanation of the drawing]

Fig. 1 is a side view of the injection molding machine according to the present invention, Fig. 2 is a sectional view of the mold, and Figs.
FIG. 2 is an explanatory diagram of the operation of the injection molding machine shown in the figure. 1... Injection device main body, 2... Heating cylinder, 3... Nozzle, 4... Slide base, 6... Mold, 9...
...Nozzle touch section, 10, 11, 12... Limit switch (detector), 13, 14, 15... Cam.

Claims (1)

[Scope of Claim for Utility Model Registration] In an injection molding machine that performs injection by touching the nozzle at the tip of the heating cylinder to the nozzle touch part of the mold where the sprue opens, the injection device body equipped with the heating cylinder is placed against the mold. A first and a second are installed on a slide base so as to be movable forward and backward, and output a signal upon detecting that the injection device main body has reached the nozzle touch setting position and the cylinder stroke end position further advanced from this position. An injection molding machine comprising a detector, and disabling injection by outputting signals from the first and second detectors.